Electric doorbell



FIG. 1 is a front view of the design;

FIG. 2 is a left view of the design;

FIG. 3 is a right view of the design;

FIG. 4 is a rear view of the design;

FIG. 5 is a top view of the design;

FIG. 6 is a bottom view of the design; and,

FIG. 7 is a perspective view of the design. 

CLAIM The ornamental design for an electric doorbell, as shown and described. 